To provide support to the National Center for Health Statistics (NCHS), CDC for audiometry testing and related questions on hearing loss and noise exposure in adolescents ages 12 to 19 years in the National Health and Nutrition Examination Survey (NHANES) for data collection year 2007. The study collects pure-tone, air conduction hearing thresholds at .5, 1, 2, 3, 4, 6, and 8 kHz in each ear separately, as well as otoscopic exams, tympanometry, and acoustic reflexes on representative samples of the non-institutionalized U.S. population in sound-treated booths meeting recommended ANSI standards. Questionnaire information about tinnitus (frequency and degree of burden), use of hearing aids and other assistive devices, as well as exposure to firearms or other sources of loud noise are collected in home interviews prior to the subjects? visit to the mobile exam centers (MECs) for audiometric exams. A similar hearing component was part of NHANES, 1999?2004, conducted on a representative sample of U.S. adults, ages 20 to 69 years. In 2005?2006, the sampled age ranges were changed to include: (a) elderly subjects, 70 years and older (not tested in FY 2007), and (b) adolescents, 12 to 19 years old. The hearing of U.S. children was last tested in 1988?1994 in NHANES III. One of the Healthy People 2010 goals is to assess (with the goal of reducing) noise-induced hearing loss in children. For this purpose, audiograms are examined and ?notches? identified in the higher frequency ranges at 3, 4 or 6 kHz as a surrogate marker of noise exposure. Computer algorithms to identify the notches have been developed. The NHANES III data serve as a baseline, but to assess progress on this goal in Healthy People 2010, hearing thresholds of U.S. children must be measured again in NHANES. NCHS directs the data collection contractor (i.e., WESTAT) in establishing and revising protocols for the hearing component and in preparing training and field manuals. NCHS provides NIDCD with an opportunity to collaboratively review summary data for purposes of quality control during the data collection period and, also, provides NIDCD with a data file for quality review approximately three months before the Public Use data release